George Stanley is a paleontologist. He studies fossils and life forms that lived in ancient oceans. Stanley is very interested in an unusual rock formation in Hells Canyon which can only be reached by hiking a steep bridge far above the Snake River.

There may be a fossil there. Hang on to that one.

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Here's another one.

I'm sitting right here on the Martin Bridge limestone, and beds just like this one have yielded hundreds of fossils. Literally thousands of fossils have come out of this bed. Bracheopods, corals, snails, clams - a whole variety of fossils have been found right in these beds, and it's what paleontologists would call a gold mine.

Limestone is a kind of rock that forms in the ocean. It consists of the skeletons of sea animals and plants. George Stanley has collected thousands of fossils from the Martin Bridge limestone. He takes them back to his lab in Montana where they undergo months of careful study.

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So you know we're prepared for the right strength. This is about seven percent or so.

In the lab the limestone is treated with hydrochloric acid. This dissolves the weak rock and leaves fossils intact.

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With this technique, intricate details are enhanced for study. The ages of the fossils are determined as well as the environment where they lived. It was soon discovered that some of the fossils from Hells Canyon were part of an ancient tropical coral reef.

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This startling discovery added another twist to the geologic story of Hells Canyon. Coral reefs only grow near the equator in warm ocean water. Yet here were parts of a fossil reef over three thousand miles north of the equator and thousands of feet above sea level. Stanley's work confirmed that the ancient rocks of Hells Canyon formed in the ocean, and they could have formed thousands of miles away in a tropical setting that bears no resemblance to Hells Canyon today.